Although Castor and Pollux are very similar stars, their asteroid belts are quite dissimilar. The Pollux Belt is little more than gravel, and commercial exploitation would be unprofitable. The Castor Belt is, on the other hand, rich in metals, ices, and simple organics, and has many large planetoids suitable for habitat construction. Consequently, Pollux is uninhabited and unvisited; Castor supports a population of five billion.

Gemini, subsector O of Solomani Rim has 19 worlds, of which 15 have native gas giants. The estimated population for the subsector is 10 billion sophonts (not necessarily humans). There are four High population (Hi) worlds, four Moderate population (Ph) worlds, four Non-industrial (Ni) worlds, four Low population (Lo) worlds, and one Barren (Ba) world. There is one Agricultural (Ag) world versus three Pre-Agricultural (Pa) worlds, and two Non-Agricultural (Na) worlds. There is one Rich (Ri) world versus one Industrial (In) world. There are two Asteroid (As) belts, no Desert (De) worlds, no Garden (Ga) worlds, no Ice-capped (Ic) worlds, two Poor (Po) worlds, two Vacuum (Va) worlds, and three Water (Wa) or Ocean (Oc) worlds. There are five Naval bases in the subsector, no Scout bases, and no Way stations. The Imperial nobility includes six Knights, two Baronets, two Barons, three Marquises, two Viscounts, no Counts, and no Dukes. The highest population worlds are Hamilcar (Solomani Rim 1738) and Castor (Solomani Rim 2339). The highest tech level is E at Hamilcar (Solomani Rim 1738) and Aristotle (Solomani Rim 1740). The average technology level is 10 (with most between 6 and 13).

Hephaistos is one of the few terraforming projects completed by the Imperium. Begun during the Interstellar Wars, the project was alternately abandoned and resumed several times. The project was finally completed by the Hephaistos Company, chartered by the Imperium in 632, and the planet was opened in 835 and sections were sold off to several colonial groups. Although the project is officially complete, work still proceeds to reduce and fine-tune the ocean and atmosphere.

Smade's Planet was settled by a single family a century ago, taking advantage of a dormant Imperial claim to the world; to date, the Solomani have not contested their presence. The Smade family, eager for news and offworld goods, welcomes visitors and traders (although local prices are extremely high).